Thermodynamics MCQ- 04

Q.1 Real gas follows which relation ?

A. PV= nRT

B. PV×compressbility factor = nRT

C. (PV)^n = RT

D. PV^n = C

Ans-: B

Q.2 1 bar is =_______.

A. 1.0197 kgf/cm^2 or 750.06 mm Hg

B. 735.6 mm Hg

C. 100 mm Hg 

D. 1.033 kgf/cm^2 or 760 mm Hg

Ans-: A

Q.3 According to james law ____.

A. Q = W/J

B. W = Q/J

C.  J = Q/W

D. W = J/Q 

Ans-: D 

Q.4 At constant pressure, when a liquid boils , the following parameter increases?

A. Enthalpy 

B. Entropy 

C. Temperature 

D. Kinetic energy 

Ans-: B

Q.5 For which process work done is zero ?

A. Constant volume 

B. Free expansion 

C. Throttling 

D. All of the above 

Ans-: D

Q.6 No liquid exists as liquid at ____.

A. Zero temperature 

B. Zero pressure 

C. Vacuum 

D. In space 

Ans-: B

Q.7 Temperature of a gas produced due to ____.

A. It's heating value 

B. Kinetic energy of molecules 

C. Surface tension of molecules 

D. Enthalpy 

Ans-: A

Q.8 According to Gay- lussac law, for a perfect gas, the absolute pressure of given mass varies directly as ___.

A. Temperature 

B. Pressure 

C. Absolute temp. , if volume is kept constant

D. All of the above 

Ans-: C

Q.9 The smallest quantity ehich take part in a chemical reaction is known as _.

A. Molecule

B. Atom

C. Carbon

D. None of these

Ans-: A

Q.10 The ratio if brake or actual work done to the indicated work done is called ?

A. Relative efficiency 

B. Mechanical efficiency 

C. Total efficiency 

D. Thermal efficiency 

Ans-: B

Q.11 For complete combustion an axcess quantity of air required in order to permit intimate mixing of fuel with oxygen is known as ___.

A. Excess fuel 

B. Excess air 

C. Oxygen 

D. All of the above 

Ans-: B

Q.12 According to Boyle's law ___.

A. PV = 0

B. PV = Constant 

C. PV = 1

D. PV = 1/2

Ans -: B

Q.13 According to first law of thermodynamics total energy of univers remain _______.

A. Constant 

B. Increases

C. Decreases

D. Zero 

Ans-: A

Q.14 In isolated system __.

A. Matter can not interchange 

B. Energy can not interchange 

C. Matter and energy can interchange 

D. A+B

Ans-: D

Q.15 In open system ___.

A. Energy can interchange 

B. Matter can  interchange 

C. A+B 

D. Energy and matter can not interchange 

Ans-: C

Heat

Heat-: Heat is a form of energy that can be move between two things when one of them is hotter then the other.

         In other words, the amount of thermal energy in a system is also known as heat.

Q. What is sensible heat ?

Ans-: The heat required to raise the temperature of 1kg of liquid from 0°C to the boilling point. Sensible heat is denoted by"h".

                   Sensible heat is related to changes temperature of gas or object with no changes in phase .

Thermodynamics MCQ-03

Q.1 The zeroth law of thermodynamics deals with ______.

A. Conversion of heat and mass

B. Reversibility of a process

C. Introduction of concept of entropy 

D. Transitivity of thermal equilibrium 

Ans-: D

Q.2 Which of the following defined specific fuel consumption?

A. Fuel consumption per hour 

B. Fuel consumption per km

C. Fuel consumption per hr per BPH

D. Fuel consumption per BPH

Ans-: C

Q.3 Combustion of gases fuels deals with _____.

A. Dalton's law

B. Avogadro's hypothesis 

C. Krichhoff's law

D. Boyle's law

Ans-: B

Q.4 A substance above critical temperature exists as_____.

A. Solid

B. Liguid

C. Vapour 

D. Supersaturated fluid

Ans-: D

Q.5 When a vapour condenses into a liquid then ____.

A. It evolves heat

B. It absorbs heat

C. No change in heat

D. Its temperature rises

Ans-: A

Q.6 On which cycle constant pressure gas cycle work ____. 

A. Otto cycle 

B. Brayton cycle

C. Rankine cycle 

D. Dual cycle 

Ans-: B

Q.7 Entropy is defined by which law?

A. Gas law 

B. First law of thermodynamics 

C. Second law of thermodynamics 

D. Zeroth law of thermodynamics 

Ans-: C

Q.8 Water is a______.

A. Substance 

B. Liquid 

C. Compound 

D. mixture 

Ans -: C

Q.9 When the cut off is _______ efficiency of diesel cycle is maximum.

A. Increased

B. Zero

C. Decreased 

D. Maximum 

Ans-: B

Q.10 Total heat of a substance is also known as ____. 

A. Entropy 

B. Calorific value 

C. Enthalpy

D. Specific heat of substance 

Ans-: C

Q.11 Heat is rejected,  In a cycle ____.

A. At constant pressures 

B. At constant volume 

C. At constant temperature 

D. At constant Enthalpy 

Ans-: A

Q.12 In the barometric reading sudden fall is the sign off approaching ____.

A. Cold wave 

B. Rain

C. Strom

D. Fine weather 

Ans-: C

Q.13 Unit of universal gas constant is ___.

A. Nm/kg mole °k

B. Nm/ kg

C. Nm/kg °k 

D. N/m/ °k 

Ans-: A

Q.14 How many value of specific heat solid and liquid have?

A. 1

B. 2

C. 3

D. 5

Ans-: 1

Q.15 In closed system ____.

A. No interchange of matter 

B. Only energy cross the boundaries 

C. Boundary can move or change position 

D. All of these 

Ans-: D 

Calorific value of fuel

Calorific value of fuel -: The combustion of fuel is accompanied by a large amount of evolution of heat. In kcal , the number of heat units evolved by the complete combustion of fuel is called the calorific value of fuel .

         

Calorific value can be determined by boy's gas calorimeter or by bomb calorimeter.

Calorific value of fuel measured in two types- 

1. Higher calorific value ( H.C.V.)

2. Lower calorific value  (L.C.V.)

1. Higher calorific value -: The amount of heat liberated by tge unit quantity of fuel i.e., 1 kg , when the products of combustion are cooled to 15° C is called higher calorific value or gross calorific value of fuel. 

2. Lower calorific value -: It is defined as ,when heat taken away by the water due to surface moisture and combustion is subtract from higher calorific value is called lower calorific value. 

 L.C.V. = H.C.V. - Heat taken by water due to surface moisture and combustion 

L.C.V. = H.C.V. - Weight of water × Latent heat

Thermodynamics MCQ-02

Q.1 A perfect gas follows which law?

A. Joules law

B. Boyle's law

C. Charles law

D. Gay -lussac law

E.  All off the above

Ans-: E

Q.2 S.I. unit of mass is ________.

A. Tonne

B. Gram

C. Kg

D. Newton

Ans-: B

Q.3 which is general gas equation?

A. PV^n = C

B. PV= nRT

C. PV= mRT

D. Cp- Cv = R/J

Ans-: C

Q.4 S.I. unit of pressure ______.

A. Bars 

B. Kg/cm^2

C. Pascal 

D. Mm of water column 

Ans-: C

Q.5 How many law's fully determined behaviour of gases? 

A. 1 law

B. 2 law

C. 5 law

D. 4 law

Ans-: D

Q.6 Ice and water form a mixture of_____.

A. Open system 

B. Closed system 

C. Heterogeneous system 

D. Isolated system 

Ans-: C

Q.7  1 N/m^2 is equal to _____.

A. 5 watt 

B. 3 watt

C. 2 watt

D. 1 watt

Ans-: D

Q.8 The unit of entropy is _____.

A. Nm/kg sec

B. J/°k

C. J/kg °k

D. J/kg

Ans-: C

Q.9 which of the following is not the property of the system?

A. Density

B. Pressure 

C. Heat

D. Temperature 

Ans-: C

Q.10 In kg one calorie us equal to _____.

A.  .0427

B.  4.27

C.  427

D.  42.7

Ans-: A

Q.11 Who developed first law of thermodynamics?

A. Kelvin

B. Joule

C. Carnot 

D. Charles

Ans-: B

Q.12 Charles law is ___. ( P is constant )

A. V=T=Constant

B. V×T×Constant 

C. V/T = Constant

D. None of these

Ans -: C

Q.13 Measurement of temperature is based on ____.

A.  Thermodynamics properties 

B.  Zeroth law of thermodynamics 

C.  First law of thermodynamics 

D.  Joules law 

Ans -: B

Q.14 At  0° C value of entropy taken as___.

A.  1

B. -1

C.  Zero 

D.  2

Ans -: C

Q.15 Thermal power plants work on which cycle?

A. Rankine cycle 

B. Otto cycle 

C. Joules cycle 

D. Carnot cycle 

Ans -: A

Thermodynamics MCQ-01

Q.1 The unit of temperature in S.I. unit _____.

A. Kelvin     

B. Celsius

C. Centigrade 

D. All of the above 

Ans.: A

Q.2 The unit of energy _____.

A. Joule/sec

B. Watt

C. Joule

D. Erg

Ans.: C 

Q.3 Erg is unit of ______.

A. Energy

B. Electric power 

C. Heat

D. Work

Ans.: B

Q.4 How many fundamental units ___.

A. 5

B. 7

C. 6

D. 9

Ans.: B

Q.5 what is the S.I. unit of power?

A. Erg

B. Newton

C. Joule

D. Watt

Ans.: D

Q.6 what is the S.I. unit of time?

A. Hour

B. Minute

C. Second

D. Day

Ans.: C

Q.7 Length is measured in ______.

A. Meter/sec

B. Km/hour

C. Meter 

D. All of the above

Ans.: C

Q.8 Internal energy of a substance depend on _______.

A. Volume 

B. Entropy 

C. Temperature 

D. Pressure 

Ans.: C

Q.9 First law of thermodynamics define ___.

A. Conservation of mass.

B. Conservation of energy.

C. Conservation of heat.

D. None of the above. 

Ans.: B

Q.10 In S.I. unit 1 bar is equal to  ____. 

A. 1 kN/m^2

B. 1×10^5 N/m^2

C. 1×10^4 N/m^2

D. 1×10^6 N/m^2

Ans.: B

Q.11 What is the value of Barometric pressure?

A. 100 mm Hg

B. 1 mm Hg 

C. 735.6 mm Hg

D. 760 mm Hg

Ans.: D

Q.12 In which cycle air refrigerators work? 

A. Otto cycle 

B. Carnot cycle 

C. Reversed joule cycle

D. Diesel cycle

Ans.: C 

Q.13  1 KWH of energy is equal to _____.

A. 3600 joule 

B. 3600 kJ 

C. 100 J

D. 36000 KJ

Ans.: B 

Q.14  which of the following measured in calorie ? 

A. Work

B. Entropy

C. Specific heat

D. Quantity of heat 

Ans.: D

Q.15 What is the unit of universal gas constant? 

A. Watts/°k

B. Erg/°k 

C. Erg cm/° k

D. None of the above 

Ans.: D

Definitions

Macroscopic approach :-               macroscopic deals with certain quantity of matter  and its behaviour. 

Microscopic approach  :-                microscopic approach concerned with molecular and atomic behaviour of energy and matter.

Thermodynamic system :--Thethermodynamic system is a fixed quantity of matter, around which we can draw a boundary. The boundary may be moveable or fixed. 

There are 3 types of system -- 

1.  Closed system :-                                             In this system there is no interchange of matter between surrounding and system . In this system only energy can cross the boundaries and the boundary also can move or change its position .

2.Open system :-                                                     In this type of thermodynamic system matter and energy both can interchange from the system.

3. Isolated  system :- 

   In this type of thermodynamic system both matter and energy no one can cross the boundaries. Isolated system not influenced by the surrounding .